Trigger slap is when the trigger is resetting while it whacks your finger. That terminology may not be correct, but our bersa .380 trigger certainly slaps me every time i shoot it. Your finger will start to go numb. Not the best for trigger control. My CZ used to but it ground out after a few hundred rounds/half dozen cleanings. I'd just clean the gun and make sure everything is in the right place. A pin may have backed out or a spring slipped out of a slot.what is trigger slap?
I did that with mine - installed Harrington firing pin and rollers. Used a little gun grease and oil in the proper places...the action is nice and sweet on mineProbably the simplest way to correct the TSP would be to install a Harrington firing pin system. Never known it to fail.
What brand of aftermarket barrel are you using?I saw an article in an issue of Shotgun News (Vol.56, Iss.12, ppg20-22) witch talks about the CZ52 and some common tuneups...sights as well as trigger creep and overtravel are discussed. And I have it from an old WW2 vet that TSP can also be dealt with by removing overtravel.
Also, a word of warning if buying an aftermarket barrel....have the headspacing measured before firing or modifying the ramp. This is so you can return it if it's wrong. Mine was too great and 9 of 10 rnds (new S&B ammo) experience spliting of the case neck...not good if you reload as I do.